Problem: A permutation p is an ordered group of numbers p1, p2, ..., pn, consisting of n distinct positive integers, each is no more than n. We'll define number n as the length of permutation p1, p2, ..., pn.

Simon has a positive integer n and a non-negative integer k, such that 2k ≤ n. Help him find permutation a of length 2n, such that it meets this equation: <image>.

Input

The first line contains two integers n and k (1 ≤ n ≤ 50000, 0 ≤ 2k ≤ n).

Output

Print 2n integers a1, a2, ..., a2n — the required permutation a. It is guaranteed that the solution exists. If there are multiple solutions, you can print any of them.

Examples

Input

1 0


Output

1 2

Input

2 1


Output

3 2 1 4


Input

4 0


Output

2 7 4 6 1 3 5 8

Note

Record |x| represents the absolute value of number x. 

In the first sample |1 - 2| - |1 - 2| = 0.

In the second sample |3 - 2| + |1 - 4| - |3 - 2 + 1 - 4| = 1 + 3 - 2 = 2.

In the third sample |2 - 7| + |4 - 6| + |1 - 3| + |5 - 8| - |2 - 7 + 4 - 6 + 1 - 3 + 5 - 8| = 12 - 12 = 0.

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;
import java.util.Arrays;
import java.util.ArrayList;
import java.lang.Math; 
import java.util.Arrays;
import java.util.Comparator;
 
 
 
public class project 
{ 
    static class FastReader 
    { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() 
        { 
            br = new BufferedReader(new
                     InputStreamReader(System.in)); 
        } 
  
        String next() 
        { 
            while (st == null || !st.hasMoreElements()) 
            { 
                try
                { 
                    st = new StringTokenizer(br.readLine()); 
                } 
                catch (IOException  e) 
                { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() 
        { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() 
        { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() 
        { 
            return Double.parseDouble(next()); 
        } 
        
  
        String nextLine() 
        { 
            String str = ""; 
            try
            { 
                str = br.readLine(); 
            } 
            catch (IOException e) 
            { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 

   

    static int binarySearch(int a[],int k,int l,int h){
        
        while(l<=h){
         int mid = (l+h)/2;
         if(a[mid]==k) return mid;
         else if(a[mid]>k) h=mid-1;
         else if(a[mid]<k) l =mid+1;
    }
        
        return -1;
    }



    static String reverse(String input)  
    { 
        char[] a = input.toCharArray(); 
        int l, r = 0; 
        r = a.length - 1; 
  
        for (l = 0; l < r; l++, r--) 
        { 
            // Swap values of l and r  
            char temp = a[l]; 
            a[l] = a[r]; 
            a[r] = temp; 
        } 
        return String.valueOf(a); 
    } 

   
    
    static int gcd(int a, int b) 
    { 
        // Everything divides 0  
        if (a == 0) 
          return b; 
        if (b == 0) 
          return a; 
       if (a == b) 
            return a; 
       if (a > b) 
            return gcd(a-b, b); 
        return gcd(a, b-a); 
    } 

    static int lcm(int a, int b) 
    { 
        return (a*b)/gcd(a, b); 
    } 

    static int solve(int A, int B) 
   { 
    int count = 0; 
    for (int i = 0; i < 21; i++) { 
        if (((A >> i) & 1) != ((B >> i) & 1)) { 
            count++; 
        } 
    } 
  
   return count;
  } 

        static long nCr(int n, int r) 
        { 
            return fact(n) / (fact(r) * 
                        fact(n - r)); 
        } 
        
        
        static long fact(int n) 
        { 
            long res = 1; 
            for (int i = 2; i <= n; i++) 
                res = res * i; 
            return res; 
        } 
        
        public static long count(long k) {
            return k * (k - 1) / 2;
        }

        static boolean isPrime(int n) { 
            // if(n==1) return false; 
            if(n==2) return true;
            if (n%2==0) return false; 
            
            for(int i=3;i<=Math.sqrt(n);i+=2) { 
                if(n%i==0) 
                    return false; 
            } 
            return true; 
        }

        static int negMod(int n){
            int a = (n % 1000000007 + 1000000007) % 1000000007;
            return a;
        }

        
        static int mod=1000003;
        public static void main(String[] args) throws Exception 
    {   
        
        OutputStream outputStream = System.out;
        PrintWriter w = new PrintWriter(outputStream);
        FastReader sc = new FastReader();
        // Scanner sc = new Scanner(new File("input.txt"));
        // PrintWriter out = new PrintWriter(new File("output.txt"));
        int i,j=0,h;
        int n = sc.nextInt();
        int k = sc.nextInt();
        
        int a[] = new int[2*n+1];
        for(i=1;i<=2*n;i++) a[i]=i;

        for(i=1;i<=k;i++){
          a[2*i] = 2*i-1;
          a[2*i-1]= 2*i;
        }
        for(i=1;i<=2*n;i++) w.print(a[i]+" ");
        w.close();
     }

       
}



// System.out.println();